A +4.0-μC charge is placed on the x axis at x = +3.0 m, and a −2.0-μC charge is located on the y axis at y = −1.0 m. Point A is on the y axis at y = +4.0 m. Determine the electric potential at point A (relative to zero at the origin).
A) 6.0 kV
B) 8.4 kV
C) 9.6 kV
D) 4.8 kV
E) 3.6 kV

Question

Quizplus · Accepted Answer

The electric potential at a point due to a point charge is given by V = k * q / r, where k is Coulomb's constant (8.99 x 10^9 N m²/C²), q is the charge, and r is the distance from the charge to the point. Calculate the potential at point A due to each charge separately and sum them. The distance from the +4.0 μC charge to point A is √((3.0 m)^2 + (4.0 m)^2) = 5.0 m, and from the -2.0 μC charge to point A is 5.0 m. The total potential is V = (8.99 x 10^9)(4.0 x 10^-6)/5.0 + (8.99 x 10^9)(-2.0 x 10^-6)/5.0 = 9.6 kV.

A +40-μC Charge Is Placed on the X Axis at X